Stupid Von Koopa is Ludwig Von Koopa's best friend (aside from Roy and Bowser Jr), and twin. He looks exactly like Ludwig, except that he has a red shell, and has red hair.
Super Mario Bros. 3
Stupid Von Koopa stole the Pipe Maze king's wand, and changed hi into a Venus Fire Trap. Then, he gave it to Ludwig Von Koopa, because Stupid was much too stupid to fight Mario so he gave it to Ludwig. "Hey! Why do I always have to fight Mario while you try to figure out how to say the alphabet?" was Ludwigs only comment. "Because I'm stupid." said Stupid.
Super Mario World
Stupid was dressed up as a Reznor in Super Mario World, and shot fireballs out of his mouth. (Ludwig put a curse on him, that whenever he talked, fire came out of his mouth) When Stupid failed to defeat Mario, the other Koopalings punched him so bad that he turned black and blue.
Mario Is Missing
Stupid doesn't appear in this game, but Ludwig mentions him.
Stupid dresses up like Ludwig for this game, because the real Ludwig got sick with the flu.
Stupid came up with the idea of making machines so that the other Koopalings can ride in them. Iggy got all of the credit though.
Mario and Luigi: Superstar Saga
Stupid appears as a fake Lemmy. He also helps Cackletta get into Bowser's body to become Bowletta. Stupid is a little smarter in this game. He also helped steal Princess Peach's voice. Also, he made Bowser fall off a cliff and get toasted into a marshmallow. (Stay on topic!)
Super Princess Peach
Stupid is the only Koopaling to appear in Super Princess Peach. He helped capture Mario Luigi, and the Toads. He also stomped a stupid fart into a flatty pancake and ate him with syrup. (Stay on topic!)
New Super Mario Bros. Wii
Stupid doesn't appear in this game, but it is rumored that he FINALLY could do the alphabet, so he helped steal Princess Peach. He also dressed up as a chain chomp and helped Iggy on his second battle. When all of the Koopalings lifted up Bowser onto his stomach, Stupid was squashed into a flatty pancake. He was also crushed underneath the falling castle. P. S. After that, he took a water bottle and ate a quarter. Then Clopsie Plupster stomped Captain Underpants into a flatty pancake and ate him with syrup.
Stupid von Koopa died when he got crushed by the castle. He does not appear in NSMB2 or NSMBU. The End. Also, Famicom launched on 1985.